1. Field of the Invention
This invention relates to a method for relatively increasing the number of hairs, for example, on the scalp of a person's head that needs more hair, or on a wig that needs supplement of hairs by securing strands of joining hair (hairs to be joined) to live hairs or artificial hairs. The invention also relates to the joining hair used for the method, and a tool or device for retaining the joining hair (i.e., joining hair retainer).
2. Description of the Related Art
Typically, two approaches are heretofore made to the problem for thickening human hair; one is a surgical hair implanting method, for thickening the hair by means of implanting hairs into the scalp of a person's head in a surgical manner, and the other is a method for securing joining hair to live hair of a person who needs more hair. The latter is further sub-divided into two; one is for attaching the joining hair to live hair by adhesive, and the other is to tie a joining hair element to the area in the vicinity of the root of individual live hair.
The surgical hair implanting method is a method for implanting a joining hair directly to the scalp of the person's head, as disclosed, for example, in Japanese Laid-Open Utility Model Publication No. Sho 56-170222 in which an anchor type joining hair is implanted in the scalp of a person's head by a needle-like device or jig designed for the exclusive use of implanting hair.
However, since the first-mentioned surgical implanting method is for implanting joining hair directly into the scalp of a person's head in order to thicken hair, this conduct falls on a general surgical treatment which can be done only by those who have a qualification certificate or license as a surgeon. Moreover, since the above method requires a special technique, it cannot be carried out easily. In addition, since hairs are implanted into the scalp, there is a possibility that various germs enter inside the scalp to cause a suppuration of the scalp or rejection (symptoms) sets in the living body.
As one of the second-mentioned methods, the method for thickening hair using an adhesive is disclosed for example in Japanese Laid-Open Patent Publication No. Sho 61-97409, in which a single strand or a group of strands of joining hair is bonded to a single strand of natural hair on the scalp of a person's head by an adhesive.
According to this method, a single strand or a group of 2 to 6 strands of joining hair cut into a proper length are aligned at one ends thereof and placed along a single strand of natural hair, and then bonded at basal end portions of the joining hairs to the root portion of the natural hair in the manner as to form a branch while applying an adhesive. As the adhesive, silicon resins, polyurethane resins or epoxy resins are used.
However, since the adhesives of silicon or polyurethane resins take long time for hardening, workability is bad. On the other hand, the adhesives of epoxy resins tend to cause itching, rash, eruption, etc. on the skin and therefore, they are not suitable in view of safety.
In order to elude these problems, there is proposed a hair thickening method in which a hot melt adhesive is used instead of the above-mentioned adhesive. This method is laid open to public inspection as the invention of the present applicant, on Jun. 28, 1991, under Japanese Laid-Open Patent Publication No. Hei 3-152205. According to this method, in order to perform the hair joining work efficiently, hairs to be joined to a single strand of a natural hair on the scalp of a person's head are beforehand grouped, for example, five (5) hair strands as one group, and the basal end portions of these joining hair strands are aligned. Then, a hot melt adhesive is applied to the grouped hair strands at areas about a few millimeters (2 to 3 mm) from the basal end portions and hardened by drying. Preferably, a plurality of grouped hair strands such obtained are beforehand prepared. For hair thickening work, one group of hair strands is spirally wound around the area in the vicinity of the root of a single natural hair strand and then the hot melt agent, which has been applied to and hardened on the basal end portion of the group of hair, is softened by heating using a suitable heating instrument such as a heating trowel, so as to be bonded to the natural hair. Thereafter, they are left as they are under normal temperature until the adhesive is cooled and hardened, whereby the joining hair is firmly attached to the natural hair.
Obviously, this method has a number of advantages, as, the joining hairs are positively attached to the natural hair and not easily come off by washing, brushing, etc., the joining hairs are not readily removed or detached even if they are exposed to and attacked by sweat, oil and hair lotion. Moreover, since the hot melt adhesive does not take long time for softening and hardening, workability is good. In addition, since the hot melt adhesive hardly reacts with the scalp, it is safe. However, since the joining hairs are attached to the natural hair in the condition that the hot melt adhesive is softened by heating, the use of an instrument such as a heated trowel is necessary when the joining hairs are attached to the natural hair. Therefore, handling is difficult. Besides, there is a possibility that the scalp is burnt when the heating trowel of high temperature is inadvertently left in contact with the scalp for a long time.
With respect to another conventional method in which joining hair is tied to an area in the vicinity of the root of the natural hair on the scalp of a person's head, a single or a few strands of joining hair are sequentially tied to the natural hair. Specifically, a single strand of natural hair is held with a finger(s) of one hand , and while maintaining this condition, a hair implanting needle held with a finger(s) of the other hand is brought into engagement with a generally central portion of a folded part of the joining hair and then, the needle is carefully manipulated so that the joining hair is wound around the area in the vicinity of the root (preferably, nearest possible area to the root) of the natural hair. Subsequently, a free end portion of the natural hair is pierced through a ring-shaped folded-back portion and tightly tied. As seen, for tying a few joining hair strands to a single natural hair strand, it is required such an extremely troublesome work that while holding the single natural hair strand with a finger(s) of one hand, a loop or ring of the joining hair is formed with a finger(s) of the other hand. Obviously, it will take a considerably long time period for the work for tying the joining hairs to, for example, 1,000 or more strands of natural hair. In addition, if the joining hairs are tied to the natural hair(s) in accordance with this conventional method, the joined hairs tend to extend, unlike the natural hair, in a horizontal direction instead of vertical direction, thus providing an unnatural outlook of the hair.
It is therefore an object of the present invention to provide a hair joining method and a joining hair used for the method in which a hair joining work can be made by anybody, in a handy manner, in a short time and yet efficiently, and which is suitable for long life and hardly susceptible to the risk for burning the scalp of a person's head.
Another object of the invention is to provide a joining hair retainer which is capable of retaining so many strands of hair as several hundreds to several thousands in the condition ready to be used by those who are engaged in a hair joining work, such as barbers or hair dressers, so that the barbers, etc. may engage themselves in a hair thickening or joining work with high efficiency whenever it is required.